DE19823792A1 - Engraving system and method with arbitrary tool path control - Google Patents

Abstract

The invention is characterized in that it comprises a toolpath generating routine and system for generating a plurality of control points directly from image data representing an image to be engraved. The control points are used to generate a toolpath which, in turn, will be used to energize an engraving head such that a tool or stylus will engrave a pattern of engraved areas in response to the toolpath. An engraving system and method for engraving at least one engraved area is shown having an engraving head tuner for tuning an engraving head such that the frequency characteristic of the engraving head defines a substantially constant gain for frequencies less than a predetermined frequency. The invention is further characterized in that it includes a system and method for interactively or automatically tuning the engraving head, interactively adjusting the filter characteristics (including the filter coefficients for the filters used on the engraving head) and for being responsive to the type of image data (whether continuous tone data or linework data). The invention is characterized in that it synthesizes the screening function so as to more accurately reproduce the image to be engraved by engraving multiple frequency cells where single cells would be engraved in the past.

Description

Cross-reference to related applications

This application is a partial continuation of the patent application with the Serial number 08 / 434.592, which was filed on May 4, 1995.

Background of the Invention 1. Field of the Invention

This invention relates to engraving and more particularly to engraving system and an engraving process to create an improved engraving image through the use of digital toolpath planning, digital fine adjustment and automatic feedback control.

2. Description of the prior art

The process of conventional electromechanical engraving consists of the end cut small areas or cells of copper from the surface of a Copper cylinder. In the conventional process, the cells are overlaid tion of a scanning signal and an image signal. The scanning signal is an AC sine wave, and the image signal is added to it to make a Cutting tool or an engraving tip moves or swings around the cells engrave.  

In the past, most efforts have been made to improve Quality of an engraved image aimed at changing the image signal. In addition, edge enhancement, selective linearization, use the faster fine adjustment of the engraving head and pulse modulation det to change the image signal accordingly, so the engraving quality can be improved. One or more of these concepts of engraving systems of the prior art disclosed in U.S. Patent Nos. 5,438,422, 5,424,845, 5,621,533, 5,329,215, 5,416,597, 5,424,846, 5,402,246, 5,454,306, 5,475,914, 5,555,473, 5,440,398, 5,493,939, 4,357,633, 4,438,460, 4,450,486, 4,451,856, 4,500,929, 5,492,057, 5,029,011, 5,519,502, 5,583,647, 5,491,559, 5,422,958, 5,293,426 and 5,617,217, disclose devices and procedures ren of the general kind, which in the past with procedures of the state the technology were used.

Thus, it should be obvious that attempts have been made to improve the engraving quality To improve, with the main focus for example on the change of the Image signal was placed.

Similarly, U.S. Patent Nos. 4,245,260 and 5,519,502 show techniques for linearization and shifting of engraved areas to a higher engraving to achieve quality. For example, U.S. Patent 5,245,260 discloses techniques to change a strobe signal to control the arrangement of the cell.  

What is needed, therefore, is a system and method that the image signal and synthesized the sampling function as a reference waveform that desired Toolpath represents the engraving tool, eliminating the need for Changes in the image and the scanning signal reduced or completely eliminated becomes.

Another problem with past approaches is that the Sampling and arrangement of cells directly from the AC (WS) - Sine wave were dependent, which eliminated the flexibility of the engraving quality was because previous sampling waves consisted of constant AC sine waves that were difficult to change in view of the image to be engraved. So what is also needed is a simple yet effective procedure and one Device for converting data with an image to be engraved in the Stand in a signal that syn. As an arbitrary tool path can be thetized, which is derived directly from the image data.

In addition, the mechanical structure of an engraving head pointed in the vergan such resonance properties that the engraving head at about 2 kHz and 5.5 kHz produced an increased output. To these unwanted resonances to eliminate, notch filters were added so that the frequency response of the Engraving head was more predictable. Because of the nature of the filtering algorithms a generally uniform but decreasing one was used for the notch filters Reaction achieved. The aforementioned U.S. Patents 4,357,633, 4,438,460, 4,450,486  and 4,500,929 disclose engraving devices and engraving methods of all common way, which filter processes of the prior art use.

Unfortunately, the conventional filtering techniques generally produced an engraving head frequency response occurring at higher frequencies, such as frequencies zen above 5.5 kHz, insufficient amplitude transmitted. In addition, allowed the prior art techniques did not apply to a user, interactive and comfortably the properties, such as the filter coefficients to change the filter to manipulate the engraving head as desired or fine adjust. In the past there were errors in the electronic comm components effects on the filter properties, and the filter properties could not move from one track to another with the required precision be transmitted.

What is needed, therefore, is a system and a method that the engraving Head digitally characterized so that the properties of the fine-tuning filter can be stored separately from the fine tuning circuit. The digital filter properties can then be archived and in the case of a scarf error with sufficient precision in the memory of an exchange circuit loaded to the desired engraving head response properties achieve.  

In the past, correcting errors or calibrating the Engraving head using different techniques in different ways carried out, such as with the help of U.S. Patents 5,029,011, 5,293,426, 5,416,597, 5,422,958, 5,438,422 or 5,440,398 techniques shown. In some calibration processes in the past, different properties became inherent properties of a single cell measured in a test cut and with a ge wanted property compared. The difference between the ge desired property and the actual property a predetermined one Tolerance value, the engraving head was adjusted accordingly. Typically are in the processes of the prior art optical devices, strobe devices and focusing devices used to make such measurements and a corresponding one Make correction. It therefore becomes a tool speed and -positioning system and a feedback system and a method needed, which is simple in construction, relatively inexpensive and easy to use is to implement.

There is therefore a need for a method and system for effective Manipulation of the arrangement of an engraved area directly from the image data, without having to use or manipulate the scanning signal.  

In the past, the head reaction characteristics were after the langwieri The fine tuning process is the result of the subjective judgment of the fine tuning adjustment quality of the fine adjustment operator. This led to fluctuations between the individual heads and made it difficult to match the engraving image quality between different engraving machines and also between heads Multi-head publication engraving machines.

It therefore becomes a method and system for automating fine tuning position process, which causes the fluctuations in the Engraving head reaction properties can be eliminated. Such a system improves the repeatability of the fine adjustment and shortens the fine adjustment position of an engraving head required time.

Summary of the invention

It is therefore a primary object of the present invention, a system and an Process for synthesizing the image data with an image to be engraved related to a desired tool path for a cutting edge to create tool, which gives greater flexibility and improved Engraving possibility and the like is made possible.  

In one embodiment, this invention includes a method of control a path of a tool in an engraving machine which follows the steps of the Generation of image data corresponding to the image to be engraved, the generation control points in response to the image data, processing the Control points for determining a tool path and the drive of the Tool for engraving a workpiece in response to the toolpath includes.

In another embodiment, this invention comprises a method of Engraving a pattern of engraved areas on a workpiece comprising the steps of generating image data corresponding to one to be engraved Image, deriving a tool path directly from the image data, using it dens the tool path for determining an engraving signal, and excitation an engraving head for engraving the workpiece using the Engraving signal.

In another embodiment, this invention includes a toolpath control for controlling a path of a tool on an engraving head an engraving machine comprising an image data processor for generating Control points in response to the image data, the image data processor further comprises a tool path generator for processing the control points,  to set a toolpath, and a signal generator that works with the Image data processor and the engraving head is coupled to the tool path received and to excite the engraving head to drive the tool to Engrave a workpiece in response to the toolpath.

In another embodiment, this invention includes an engraving machine for engraving a workpiece, comprising an engraving bed, an engraving head, which is located on the engraving bed, around at least one engraved area on the To engrave the workpiece, the engraving head comprising a tool, a Processor coupled to the engraving head to receive and image data also an engraving signal for engraving at least one engraved area and a digital toolpath planner that works with the processor Connected to a toolpath in response to the image data generate, with the processor using the toolpath to generate the engraving signal to create.

In a further embodiment, this invention comprises a method for Generation of an engraving signal for controlling an engraving head, so that a Tool on the engraving head follows a desired tool path, whereby the Process the steps of generating an engraving signal and processing of the engraving signal to create an engraving head frequency response,  which sets a substantially constant gain for frequencies which are smaller than a predetermined frequency.

In another embodiment, this invention comprises an engraving head fine adjuster for fine adjustment of an engraving head so that a tool on the Gra four-head follows a desired tool path, with the engraving head fine a processor for receiving an engraving signal and also for ver work of the engraving signal includes to generate an engraving head frequency response create an essentially constant gain for frequencies specifies that are smaller than a predetermined frequency.

In another embodiment, this invention includes an engraving machine for engraving at least one engraved area, the engraving machine an engraving bed comprises an engraving head which is connected to the engraving bed stands, the engraving head a tool and an engraving head fine adjuster comprises, which is coupled to the engraving head to ver an engraving signal work to create an engraving head frequency response which involves an im substantial constant gain for frequencies that are smaller than one predetermined frequency.  

In another embodiment, this invention comprises a method of Fine tuning an engraving head comprising the steps of use at least one filter for filtering an engraving signal to avoid unwanted Eliminate resonances, creating a filter coefficient for at least a filter, coupling a user interface to at least one Filter, determining whether at least one parameter for at least one filter needs to be changed using the user interface to set at least one parameter in a programmable manner if at least one parameter has to be changed.

In a further embodiment, this invention comprises an engraving machine, comprising an engraving bed, an engraving head, which with the engraving bed in the Connection is, where the engraving head is a cutting tool and min at least includes a filter associated with the engraving head, where at least one filter has at least one parameter and at least one Includes filter coefficients, and a user interface connected to at least one Filter is coupled, wherein the user interface enables a user offset to set at least one parameter in a programmable manner to to change a response property of the filter.  

In another embodiment, this invention comprises a speed speed sensor for recording a position of a cutting tool for engraving a cylinder, comprising a rotor for holding the cutting tool, at least one electromagnetic drive, comprising at least one type drive coil around this to make the rotor vibrate when at least one drive coil is energized, and a sensor operating in Relation to the at least one electromagnetic drive is related to a Determine cutting tool position in response.

In another embodiment, this invention comprises a method for Stabilization of an engraving head, comprising a motor for driving a Cutting tool comprising the steps of energizing the motor with a first drive signal applied to a first coil of determining one Motor speed with the help of a second coil, and stabilizing the Engraving head with the help of motor speed.

In another embodiment, this invention includes an engraving machine for engraving at least one engraved area, the engraving machine includes an engraving bed, an engraving head, which together with the engraving bed Hang stands, the engraving head comprises a rotor on which a cutting unit is attached, an engraving head fine adjuster, which is coupled to the engraving head  pelt is to process an engraving signal to create a processed signal fen, which includes a frequency response that is substantially constant Sets gain for frequencies that are smaller than a predetermined one Frequency, at least one electromagnetic drive at least one Drive coil comprises, wherein at least one electromagnetic drive in operational relationship with the runner is to set the runner in vibration zen when at least one drive coil is excited with the processed signal, and a sensor operatively related to at least one electromagnetic Drive stands at a speed of electromagnetic drive as In response to this, the engraving head adjuster determines the engraving Head resonance in response to the speed and the processed signal fine-tuned.

In a further embodiment, this invention comprises a method for Scaling of image data to be engraved, the method taking the steps of Generating image data corresponding to an image to be engraved, the Determine whether the image data is halftone or linework data, generating either halftone control points or Linework checkpoints when it is determined whether the image is data is semitone or linework data.  

In another embodiment, this invention includes an engraving machine for engraving a workpiece, comprising an engraving bed, an engraving head, which is located on the engraving bed, around at least one engraved area on the To engrave the workpiece, the engraving head comprising a tool, a Processor coupled to the engraving head to receive and image data also an engraving signal for engraving at least one engraved area to generate, and a digital toolpath planner that with the processor in Connected to a toolpath in response to the image data plan with the processor using the toolpath to get the engraving signal to create.

In a further embodiment, this invention comprises a method for Controlling a path of a tool in an engraving machine, comprising the Steps of generating image data corresponding to an image to be engraved; creating control points in response to the image data; of the ver working the control points to determine a tool path; and the Driving the tool to a workpiece in response to the toolpath to engrave.

In addition, it is another object to provide a method for controlling a path of a tool in an engraving machine with one or more of the following additional or optional features (either alone or in combination):

• - Processing the image data to a predetermined number Create density values, and use the predetermined number of Density values for determining an overall image density in percent;
• - Using the predetermined number of density values for Determination of a center of density;
• - Determination of an entry control point at which the tool in the workpiece enters;
• - Determination of an exit control point at which the tool exits the workpiece emerges;
• - Determination of at least one further control point between the Entry control point and exit control point;
• - Determination of a middle control point between the entrance checkpoint and exit checkpoint;
• - Use of the entry control point, the exit control point and the middle control point to determine the tool path;  
• - Determination of a middle control point between the entrance checkpoint and exit checkpoint;
• - Adaptation of a curve to the entry control point, the exit control point and the middle control point for defining the tool way;
• - Determination of a middle control point according to the Center of an image density;
• - Determination of a total image density in percent for the image data;
• - Use the total image density in percent to determine the Entry control point and exit control point;
• - Establishment of the entry control point and the exit control point on a surface of the workpiece;
• - Arrangement of the entry control point and the exit control point around the middle control point;  
• - Establishment of the entry control point and the exit control point below a surface of the workpiece if the total density is in Percent exceeds a predetermined percentage,
• - the predetermined percentage being at least 90%;
• the image data comprising first image data and second image data, the method further comprising the following steps:
• - Determining whether an image data sum from the first image data and second image data comprises a majority of the density for all image data;
• - the division of the first image data and the second image data into one first image data subset and a second image data subset;
• the generation of control points for the first image data Sub-group and the second image data sub-group;
• the image data comprise a plurality of image data groups, the method further comprising the following steps:  
• determining whether a summed density for the plurality of images data groups comprises a majority of the density for all image data;
• - the division of the plurality of image data groups into a plurality on image data subgroups;
• - The creation of control points for each individual image data sub group;
• - The adaptation step further comprises the following steps:
• - the use of an interpolation routine of a cubic spline during the adjustment step;
• - determining a frequency of image data values for display of an engraved area to be engraved on the workpiece by one create a predetermined number of density values;
• determining an overall image density in percent using the predetermined number of density values;
• - the identification of an entry control point, an exit control troll point and a third control point between the entry and the Exit control point;  
• - using the entry control point, the exit control point and the third control point for determining the tool path;
• - the establishment of a middle control point corresponding to a middle an image density;
• - Setting up the entry control point and the exit control point below a surface of the workpiece if the total density is in Percent exceeds a predetermined percentage;
• - the predetermined percentage being at least 90%;
• - determining whether the image data is semitone data or Stroke work data;
• - Generating either a halftone pulse frequency divider or one Line work pulse frequency divider when it is determined that the Image data is semitone data or line work data;
• - Applying the halftone pulse frequency divider or Line work pulse frequency divider at the control points before processing step.

Another embodiment of the invention relates to the creation of an engraving machine for engraving a workpiece, consisting of an engraving bed; an engraving head, which is located on the engraving bed, by at least one to engrave the engraved area on the workpiece, the engraving head being a work stuff includes; a processor device coupled to the engraving head to To receive image data and also around an engraving signal for engraving the minde at least create an area; and a digital toolpath planner direction associated with the processor device to one Plan toolpath in response to the image data, with the processor pre direction used the toolpath to generate the engraving signal.

Another object of the invention is to provide an engraving machine for engraving a workpiece with one or more of the following additional or optional features (either alone or in combination):

• - a tool path data signal processor device for reception digital image data related to an image to be engraved, and in response to generating the toolpath;
• a tool path data signal processor device for receiving the Image data related to an image to be engraved and the Creating a plurality of control points in response thereto;  
• a curve fitting device for receiving a plurality of Control points and to fit a curve to it, the curve being the Sets toolpath;
• a curve fitting device for receiving the plurality of Control points and to fit a curve to it, the curve being the Sets toolpath;
• - The majority of control points generally an on step point, with the tool starting one of the at least to engrave an engraved area, an exit point at which the work witness from which the at least one engraved area emerges, and a third Checkpoint located between the entry point and the exit point;
• - The third point comprises a center, that of a density center which corresponds to image data;
• - wherein the processor device processes the image data by one create a predetermined number of density values, with the processor pre direction further includes:  
• an image density determination device for receiving the previously determined number of density values and for determining an overall image density in percent;
• - wherein the processor device further comprises:
• a density center determining device for receiving the previously certain number of density values and to use the predetermined Number of density values to determine a density center;
• - wherein the processor device receives the image data and one Total image density in percent determined and the total image density in percent used a plurality of control points to determine a work to determine the tool path;
• - wherein the tool path data signal processor the entry control point and the exit control point on a surface of the workpiece Establishes the occurrence of a predetermined condition;
• - The predetermined condition comprises a density that is low is greater than a predetermined density;
• - the predetermined density being less than 90%;
• the image data comprising first image data and second image data, the processor device further comprising:  
• a double frequency determining device for determining whether a summed image density for the first image data and the second image data Includes majority of density for all image data;
• - The double frequency determiner the first image data and the second image data into a first image data subgroup and a second image data Subgroup splits when the image density exceeds a majority, and Kon troll points for both the first image data subgroup and the second Image data subset created;
• - The curve adjuster further an interpolation routine includes cubic spline for generating the tool curve.

Another object of the invention is to provide a method for generating supply an engraving signal to control an engraving head, so that a tool on the engraving head follows a desired tool path, the process being the Steps of generating an engraving signal and processing the engraving signals to create an engraving head frequency response, which one in sets substantially constant gain for frequencies that are less than a predetermined frequency.

Another object is to provide a method of generating an engraving signal to control an engraving head with one or more of the following additional or optional features (either alone or in combination):

• - Processing the engraving signal to create a processed one Signal, which is a substantially constant gain for frequencies specifies that are less than 10 kHz;
• - The method further comprises the following step:
• - Execution of the processing step using at least one filter to match the natural resonances of the engraving head counteract;
• - The method further comprises the following step:
• Application of at least one boost filter to the engraving signal, to amplify the response of the engraving head at frequencies above one Raising frequency are, but are smaller than the predetermined frequency;
• - The method further comprises the following step:
• - Execution of the processing step using min least a filter to counter the natural resonance of the engraving head to act;  
• - The boost frequency is at least 1 kHz;
• - The at least one filter is an infinite impulse word filter includes;
• - The boost filter is an infinite impulse response filter includes;
• - The production step further comprises the following steps:
• - the generation of image data according to an image to be engraved;
• - creating control points in response to the image data;
• - Processing the control points to close the toolpath define; and
• - generating the engraving signal using the control Points;
• - The method further comprises the following step:
• - Use a user interface to at least one Define parameters related to the at least one filter stands.

Another object of the invention is to provide an engraving head fine for fine adjustment of an engraving head, so that a tool on the engraving head follows a desired tool path, with the engraving head fine adjuster includes a processor to receive an engraving signal and also to do so Process the engraving signal to create an engraving head frequency response which sets a substantially constant gain for frequencies which are smaller than a predetermined frequency.

In addition, it is another object to provide the aforementioned engraving head fine adjuster with one or more of the following additional or optional features, either alone or in combination:

• - The engraving head fine adjuster processes the engraving signal to to create a processed signal comprising the frequency response which a sets essentially constant gain for frequencies less than 10 kHz;
• the engraving head fine adjuster comprises at least one filter, to counteract the natural resonance of the engraving head;
• - Wherein the engraving head fine adjuster further at least one Anhe Exercise filter includes to amplify the engraving signal at frequencies that are larger are as a boost frequency, but less than the predetermined frequency;  
• - Wherein the engraving head fine adjuster further at least one filter includes to counteract the natural resonances of the engraving head;
• - Wherein the engraving head fine adjuster further at least one Anhe Exercise filter includes to amplify the engraving signal at frequencies that are larger are as a boost frequency, but less than the predetermined frequency;
• - The boost frequency is at least 1 kHz;
• - The at least one filter is an infinite impulse response filter includes;
• - The boost filter is an infinite impulse response filter includes;
• - The at least one filter and the boost filter each one include infinite impulse response filters;
• - With the engraving head fine adjuster to the digital tool path processor is coupled, comprising:
• - A control point generator for receiving image data that a correspond to the engraved image and to generate control points as Response to this; and
• - an interpolator to receive the control points and to generate them the engraving signal in response thereto;  
• - The engraving head further a speed sensor for Determine a position of a cutting tool for engraving a cylinder which includes;
• - The engraving head further a runner to hold the cutting edge tool includes;
• - At least one electromagnetic drive at least one Drive coil encircled all around to vibrate the rotor, when the at least one drive coil is energized;
• - The speed sensor further comprises:
• - A pickup coil that is around the at least one electro magnetic drive is arranged; and
• a pickup circuit which is coupled to the pickup coil, to measure a speed of the runner and to measure the speed in convert the cutting tool position.

Another object of the invention is to provide an engraving machine for Engrave at least one engraved area to create the engraving machine includes an engraving bed, an engraving head, which with the engraving bed in the Connected, wherein the engraving head comprises a tool; and one Engraving head fine adjuster, which is coupled to the engraving head, for an engraving  signal to create an engraving head frequency response which sets a substantially constant gain for frequencies that are smaller are as a predetermined frequency.

In addition, it is another object to provide the aforementioned engraving machine with one or more of the following additional or optional features, either alone or in combination:

• - The engraving head fine adjuster processes the engraving signal to to create the engraving head frequency response, which is a substantially con sets constant gain for frequencies less than 10 kHz;
• the engraving head fine adjuster comprises at least one filter, to counteract the natural resonance of the engraving head;
• - Wherein the engraving head fine adjuster further at least one Anhe Exercise filter includes to amplify the engraving signal at frequencies that are larger are as a boost frequency, but less than the predetermined frequency;
• - Wherein the engraving head fine adjuster further at least one filter includes to counteract the natural resonances of the engraving head;
• - Wherein the engraving head fine adjuster further at least one Anhe Exercise filter includes to amplify the engraving signal at frequencies that are larger are as a boost frequency, but less than the predetermined frequency;
• - The boost frequency is at least 1 kHz;  
• - The at least one filter is an infinite impulse word filter includes;
• - The boost filter is an infinite impulse response filter includes;
• - The at least one filter and the boost filter each include an infinite impulse response filter;
• - With the engraving head fine adjuster on a digital tool path signal is coupled, consisting of a control point generator to image data to receive that correspond to an image to be engraved, and for control points in response, and an interpolator to receive the Control points and for generating the engraving signal in response thereto;
• - The at least one boost filter at least one Includes parameters for the engraving head adjuster, further comprising a filter processor is provided, which is coupled to the at least one boost filter, wherein the filter processor has a user interface for programming the at least one comprises a parameter which with the at least one boost filter in Is related;
• - The at least one boost filter at least one Includes parameters for the engraving head adjuster, further comprising a filter processor is provided, which is coupled to the at least one filter, the filter  processor a user interface for programming the at least one Includes parameters associated with the at least one filter;
• - The engraving head further from a speed sensor for determining a position of a cutting tool for engraving a Cylinder exists;
• - The engraving head further from a rotor to hold the Cutting tool consists of at least one electromagnetic drive includes at least one drive coil around it to keep the rotor in To vibrate when the at least one drive coil is excited, the speed sensor further consists of a sensor coil that rings is arranged around the at least one electromagnetic drive, and one Sensor circuit that is coupled to the sensor coil at a speed of the runner and measure the speed in the cutting tool position convert.

Another object of the invention is to provide a method for To fine-tune an engraving head, consisting of the steps of Using the at least one filter to filter an engraving signal to eliminate unwanted resonance, creating a filter coefficient for the at least one filter; coupling a user interface to the at least one filter, determining whether at least one parameter for the at least one filter needs to be changed, using the user  interface to the at least one parameter in a programmable manner to be set if the at least one parameter has to be changed.

In addition, it is another object to provide the aforementioned method with one or more of the following additional or optional features either alone or in combination:

• - The determining step further comprises the step of determining whether either a frequency or a notch depth needs to be changed;
• - wherein at least one parameter comprises a frequency;
• - wherein at least one parameter comprises a notch depth;
• - the further step of coupling a processor to the minde at least a filter;
• - the automatic setting of at least one parameter under Use of the processor in response to an automatic fine adjustment advancement;
• - Using the user interface to the programmable Setting the at least one parameter so that the at least one filter is a sets essentially constant gain for frequencies less than a predetermined frequency;
• - The predetermined frequency is less than about 10 kHz;  
• - The method further comprises the following step:
• - using the user interface for setting at least a parameter of at least one boost filter to determine the response of the Gra four head to amplify at frequencies beyond a boost frequency;
• - The boost frequency is at least 1 kHz;
• - The at least one filter is an infinite impulse response filter includes;
• - The step of automatic adjustment continues the following Step includes:
• - Using a sensor to determine a position of a Cutting tool for engraving a cylinder;
• - Using the position determined by the sensor for through leading the step of automatic adjustment;
• - The sensor comprises a speed sensor;
• the method further comprises the following steps: arranging a sensor coil around at least one electro magnetic drive on the engraving head; and  
• - coupling a sensor circuit to the sensor coil for measurement a speed of the runner and to convert the speed into the cutting tool position.

Another object of the invention is an engraving machine ne to create, including an engraving bed, an engraving head, which with the Gra quadruple is related, the engraving head being a cutting tool includes; and at least one filter associated with the engraving head stands, wherein the at least one filter comprises at least one parameter and at least one filter coefficient; and a user interface to the at least one filter is coupled, the user interface being a Gives the user the ability to programmably program the at least one Set parameters to change a response characteristic of the filter.

In addition, it is another object to provide the aforementioned engraving machine with one or more of the following additional or optional features, either alone or in combination:

• - The at least one parameter being a frequency and a notch depth includes;
• - The at least one parameter comprising a frequency;
• - The at least one parameter comprises a notch depth;  
• - Wherein the engraving machine further comprises a processor, the zwi the user interface and the at least one filter are coupled, wherein the processor has a device for automatic adjustment of the minde least one parameter in response to an automatic tuning request change includes;
• - The user interface for programming a device baren setting of the at least one parameter includes, so that the at least a filter is a head reaction with substantially constant gain for Specifies frequencies that are less than a predetermined frequency;
• - The predetermined frequency is less than about 10 kHz;
• - The user interface for programming a device setting of at least one parameter of at least one Emphasizing filter associated with the engraving head to the response of the engraving head at frequencies above a boost frequency to step out;
• - The boost frequency is at least 1 kHz;
• - The at least one filter is an infinite impulse response filter includes;
• the device comprises an infinite impulse response filter, coupled to an interactive user interface;  
• the device comprises an infinite impulse response filter, coupled to an interactive user interface;
• - The engraving head further a speed sensor Determination of a position of a cutting tool for engraving a cylinder which includes;
• - The engraving head further a runner to hold the cutting edge Tool includes, comprising at least one electromagnetic drive at least one drive coil around it to vibrate the rotor move when the at least one drive coil is energized, the Ge speed sensor further comprises a sensor coil, which around the at least an electromagnetic drive is arranged, and a sensor circuit, the is coupled to the sensor coil to measure a speed of the rotor, and to convert the speed to the cutting tool position.

Another object of the invention is to provide a method for stabilizing a To create engraving head, comprising a motor for driving a cutting edge tool comprising the steps of energizing the motor with a first Drive signal applied to a first coil of determining one Motor speed with a second coil, and stabilizing the engraving head with the help of engine speed.  

In addition, it is another object to provide the aforementioned method with one or more of the following additional or optional features either alone or in combination:

• - The second coil comprises fewer than five turns, which are round are arranged around the engine;
• - the method further comprising the step of determining a cut The tool position for the cutting tool includes, which with the sensor certain cutting tool position, motor speed and the first Drive signal is used to carry out the stabilization.

Another job is to have an engraving machine for engraving to create at least one engraved area, the engraving machine Engraving bed includes an engraving head, which together with the engraving bed Hang stands, the engraving head comprises a rotor on which a cutting unit is attached, an engraving head fine adjuster, which is coupled to the engraving head pelt is to process an engraving signal to create a processed signal fen which comprises a frequency response which is a substantially constant Sets gain for frequencies that are smaller than a predetermined one Frequency, at least one electromagnetic drive at least one Drive coil comprises, wherein the at least one electromagnetic drive in operational relationship with the runner is arranged to vibrate the runner move if the at least one drive coil with the processed signal is excited, and a sensor that is operationally related to the least  an electromagnetic drive is arranged at a speed of Determine runner in response, with the engraving head fine adjuster Engraving head resonance in response to the speed and the processed Fine-tuned signal.

In addition, it is another object to provide the aforementioned engraving machine with one or more of the following additional or optional features, either alone or in combination:

• - The sensor comprises a sensor coil, which around the at least one electromagnetic drive is arranged;
• - A sensor circuit, which is coupled to the sensor coil to a Speed of the runner and measure the speed in the Convert cutting tool position;
• - The sensor coil is a rate of change of flow through which measures at least one drive coil;
• - With the sensor coil no more than five turns around the includes electromagnetic drive;
• - The engraving head fine adjuster processes the engraving signal to to provide a processed signal comprising a frequency response which is a  sets essentially constant gain for frequencies less than 10 kHz are;
• the engraving head fine adjuster comprises at least one filter, to counteract the natural resonance of the engraving head;
• - Wherein the engraving head fine adjuster further at least one Anhe Exercise filter includes to amplify the engraving signal at frequencies that are larger are as a boost frequency, but less than the predetermined frequency;
• - Wherein the engraving head fine adjuster further at least one filter includes to counteract the natural resonances of the engraving head;
• - Wherein the engraving head fine adjuster further at least one Anhe Exercise filter includes to amplify the engraving signal at frequencies that are larger are as a boost frequency, but less than the predetermined frequency;
• - The boost frequency is at least 1 kHz;
• - The at least one filter is an infinite impulse response filter includes;
• - The boost filter is an infinite impulse response filter includes;
• - The at least one filter and the boost filter each one include infinite impulse response filters;  
• - With the engraving head fine adjuster on a digital tool path signal processor is coupled, comprising a control point generator for Reception of image data which correspond to an image to be engraved and for Generating control points in response, and an interpolator to Receiving the control points and generating the engraving signal in response thereon.

Another object of the invention is a method for scaling to create image data to be engraved, the method taking the steps of Generating image data that corresponds to an image to be engraved, the Determine whether the image data is halftone data or Line work data is about creating either halftone control points or linework control points if it has been determined that the Image data is semitone data or line work data.

In addition, it is another object to provide the aforementioned method with one or more of the following additional or optional features either alone or in combination:

• - the process further comprising the steps of processing the control points included to set a toolpath and energize a gra four-head to engrave a workpiece in response to the toolpath;
• - the method further comprising the step of applying either one Halftone pulse frequency divider or a line work pulse frequency divider  the image data includes if it is determined during the determining step, that the image data is halftone data or line work data is about the halftone control points or the stroke work control points produce.

Another object of the invention is to provide an engraving machine for To create an engraving of a workpiece that includes an engraving bed Engraving head, which is located on the engraving bed, by at least one engraved To engrave the area on the workpiece, the engraving head comprising a tool, a processor coupled to the engraving head to receive image data and also an engraving signal for engraving the at least one engraved one Area, and a digital toolpath planner that works with the Processor for planning a toolpath in response to the image data in the Connected, where the processor uses the toolpath to Generate engraving signal.

In addition, it is another object to provide the aforementioned engraving machine with one or more of the following additional or optional features, either alone or in combination:

• - The processor further comprising a tool path data signal processor for receiving digital image data comprising a picture to be engraved in the  Are related, and to generate the toolpath in response thereon;
• - wherein the tool path data signal processor has a pulse frequency Dividing device for generating image data includes one to be engraved Match Image to determine whether the image data is halftone or stroke work data, and either halftone control points or To produce stroke work control points when it is determined that it is at the image data is halftone data or stroke work data;
• - wherein the tool path data signal processor continues a pulse frequency dividing device for processing the control points to the Define toolpath and excite an engraving head to a workpiece Engrave in response to the toolpath;
• - wherein the pulse frequency divider device is either a semitone Pulse frequency divider or a line work pulse frequency divider on the picture applies data if it was determined during the determining step that the image data is halftone data or line work data to generate the halftone control points or the stroke work control points.

Further objects and advantages of the invention will be apparent from the following writing, the accompanying drawings and the appended claims obviously.  

Brief description of the attached drawings

Fig. 1 is a perspective view of an engraving, which comprises features of the present invention;

Fig. 2 is a schematic diagram showing a processor according to an embodiment of the invention;

Fig. 3 is an illustration of image data, control points that have been generated using the image data, and a tool path of points by means of the control is generated,

Fig. 4 is an illustration of image data, control points generated using the image data, and a toolpath generated by the control points;

FIG. 4A is an illustration of image data, control points that have been generated using the image data, and a tool path, the score of the control was produced;

Figures 5A and 5B collectively illustrate a system and method or routine for creating checkpoints, such as the checkpoints shown in Figure 3;

Fig. 6 is a further schematic diagram of a synchronization routine according to an embodiment of the invention;

Fig. 7 is a schematic view of a system and a routine of a fine adjustment process;

Fig. 8 is a schematic view of an automatic fine adjustment of the user interface routine according to an embodiment of the invention;

Fig. 9 is a graphical view of a typical reaction of an engraving head of the prior art;

Fig. 10 is a graphical view of a reaction of an engraving head of the prior art, after a notch filtering;

Fig. 11 is a graphical view of response characteristics of the engraving head after the filtering according to the present invention;

Fig. 12 is a view of a user interface according to an embodiment of the present invention;

Fig. 13 is a sectional view of an engraving head motor showing a rotor and a speed sensor coil associated with a pair of electromagnets;

Fig. 14 is a schematic representation of a Schneidewerkzeug- velocity and position extraction circuit according to one embodiment of the present invention;

Fig. 15 is an overall schematic diagram of an operation of the system and the routine of the present invention, at system power;

FIG. 16 is an engraved with the features of the present invention shows Kanji character; and

Fig. 17 shows a Kanji character engraved with a prior art device.

Detailed description of the preferred embodiments

Fig. 1 is a perspective view of a preferred embodiment of a Gra four machine, commonly referred to as the engraving machine 10 . In the described embodiment, the engraving machine 10 is an engraving machine, but the invention is also applicable to other types of engraving machines. The engraving machine 10 can be surrounded by a displaceable safety housing, which is not shown here for the sake of clarity. The engraving machine 10 comprises a machine bed 12 with a headstock 14 and a tailstock 16 , which are slidably mounted in a track 18 , so that the headstock 14 and the tailstock 16 can move towards and away from each other. For this purpose, the engraving machine 10 comprises a plurality of linear travel drives or a first Antriebsmotorvor direction or a first drive motor 20 and a second Antriebsmotorvor direction or a second drive motor 22 , which are each capable of the headstock 14 and the tailstock 16 towards and from each other move away. The drive motors can move the headstock 14 and tailstock 16 to a fully retracted position, for example, or move to a cylinder stop position, as shown in FIG. 1.

The drive motors 20 and 22 can be operated separately, so that the headstock 14 and the tailstock 16 can be controlled either independently or together. Although not shown here, only a single drive motor with a lead screw (not shown) with opposing threads (not shown) can be used, the two spindles ensuring that the headstock 14 and the tailstock 16 move towards one another or be moved away from each other when the lead screw is driven. The use of separate drives for the headstock 14 and tailstock 16 enables cylinders 24 of different lengths to be loaded with the aid of, for example, a overhead traveling crane, the travel of which, for example, runs at right angles to the axis of rotation of the cylinder 24 . However, it should be noted that a fixed headstock 14 and tailstock 16 can be used in conjunction with a driven tailstock 16 or headstock 14 when, for example, a cylinder loading mechanism (not shown) loads the cylinder 24 by loading it into a Direction moves, which is generally parallel to the axis of rotation of the engraving machine 10 .

As best shown in Fig. 1, the cylinder 24 includes a first end 24 b and a second end 24 c, both of which have receiving openings (not shown) for receiving the ends 16 a and 14 a, respectively. In general, the ends 14 a and 16 a have a conical shape and correspond to the shape of the receiving openings in order to hold the cylinder 24 at an engraving station 26 of the engraving machine 10 . If, although not shown, a cylinder is to be engraved with a shaft, then the headstock 14 and tailstock 16 would each include a jig or chuck (not shown) to rotatably hold the cylinder 20 at the engraving station 26 .

The engraving machine 10 also includes an engraving head 28 with a cutting tool or an engraving tip 30 (engraving stylus) for engraving an upper surface 24 a on the cylinder 24 . In the exemplary embodiment described, the surface 24 a preferably has a copper coating of the type used in engraving. The engraving head 28 is slidably mounted on a carriage 32, so that a third driving apparatus or a third drive motor 27 move the engraving head 28 in a generally radial direction with respect to the central axis of the cylinder 24 to the cylinder 24 toward and away. The carriage 32 is also slidably mounted on the machine bed 12 so that it can traverse the entire surface 24 a of the cylinder 24 in the direction of the double arrow 36 from FIG. 1. Note that this direction is generally parallel to the axis of the cylinder 24 . The engraving machine 10 also includes a lead screw (not shown) and drive motors (not shown) to move the carriage 32 in the direction of the double arrow 36 . Various features of the following patents that can be used in the engraving system and method of the present invention are similar to those found in U.S. Patent Nos. 5,424,845, 5,424,846, 5,438,422, 5,440,398, 5,454,306 , 5,492,057 and 5,329,215, which have been assigned to the same assignee as the present invention and which are incorporated by reference into the present invention as their constituent parts.

The engraving machine 10 also includes a drive device or a drive motor 11 , while it rotatably drives the support shaft 14 a to drive the cylinder 24 in a rotatable manner when it is excited by an engraving control 38 . In this regard, the engraving machine 10 includes the engraving controller 38 which generally controls the operation of the engraving machine 10 and also controls all of the drive motors, such as the drive motors 11 , 20 , 22 and 27 . The drive motors 11 , 20 , 22 and 27 optionally respond to the engraving control 38 .

The engraving machine 10 further comprises an image processing device or an image processing computer 40 , which is coupled to the controller 38 in order to generate digital image data which are associated with an image to be processed and / or to be engraved by the engraving machine 10 . A suitable image processing computer 40 is the image processing workstation, model no. IPW-2000, available from Ohio Electronic Engravers Inc. of Dayton, Ohio, which is the assignee of the present invention.

A feature of the present invention is that it provides an apparatus for generating a toolpath that is traced by the engraving tip 30 to engrave a number of engraved areas in response to a stream of digital image data. In this regard, the engraving machine 10 includes at least one digital signal processor or processing device (shown schematically as block 42 in FIG. 1) coupled to the controller 38 to process any image data or signals received from the controller 38 . filter and adjust the received signal in response to various feedback information in the manner described below. The processing device 42 is also coupled to an amplifier 53 to a signal generated by the processing device to amplify for transmission to an engraving head 28, to energize the engraving head 28 so that it moves the engraving tip 30, engraved to form a pattern To engrave areas on the cylinder surface 24 a.

As best shown in FIG. 2, the digital signal processor 42 includes a toolpath device or toolpath controller 44 to create an engraving toolpath that is traced by the engraving tip 30 to perform the engraving.

In general, the processor 42 capable of a plurality of digital control points such as the points 62 a- 62 is to generate i in Fig. 3, in response to a digital image data stream 60, which is received by the Graviersteuerung 38. The engraving controller 38 receives the digital image data stream 60 from the previously mentioned image processing computer 40 ( FIG. 1). The method and apparatus for generating the control points from the digital image data and for generating an engraving tool path in response to these control points will now be described with reference to FIGS. 2-6.

As shown in Fig. 2, the processor 42 includes the tool path controller 44 comprising a forming apparatus or a generator 46 for receiving the digital image data from the controller 38 and for generating a plurality of control points, such as the aforementioned control points 62 a- 62 i, which are shown in Fig. 3. The generator 46 receives the image data in the form of the stream 60 ( FIG. 3) of digital density values, such as e.g. B. the density values, which in Fig. 3 with 60 a, 60 b,. . . 60 l are marked. To simplify the illustration, the density values are shown as percentages, with 0% density representing a white or non-engraved area and 100% density representing a completely black engraved area.

In the described embodiment, stream 60 of digital density values includes four ( 4 ) data values for each area to be engraved. The control point generator 46 receives the data values and generates the plurality of control points 62 a-62 i (Fig. 3) in response thereto. Thus, for example, the image data values 60 a- 60 d from the image data stream 60 received from the generator 46, and it is in response to a plurality of corresponding control points 62 a-c generates the 62nd

The tool path control 42 also includes a curve fitter / Werkzeugweggenerator 48, the a plurality of control points 62 62 i, and generates a tool path in response thereto, such as the tool path 64 in FIG. 3. For purposes of illustration with respect to FIG. 3 section 64 a of tool path 64 is generated with the aid of the generated control points 62 a- 62 c. Similarly, the section 64 b and 64 c of the tool path 64 with the aid of the control points 62 d 62 f or 62 g i generated 62nd

In the described embodiment, the curve adjuster / toolpath generator 48 includes a cubic spline interpolator or curve fitting routine or device that is present in appropriate memory (not shown) of processor 42 to receive control points, such as the points 62 a- 62 i, and to generate the toolpath 64 in response. In the described embodiment, the generator 48 interrupts the tool path 64 in 32 separate data segments, one of which is shown as 64 d in FIG. 3. These 32 separate data segments are ultimately transferred to the fine adjustment processor 52 , as will be described in more detail later. In this regard, curve fitting techniques described in Numeric Recipes in C the Art of Scientific Computing, second edition, Cambridge University Press, Section 3.3 - Cubic Spline Interpolation, can be used to fit a curve to the control points processed.

The digital signal processor 42 and tool path controller 44 further include a synchronization device or routine 50 for receiving machine synchronization signals from the engraving controller 38 and for synchronizing the digital tool path 64 with the rotation of the cylinder 24 . The operation of the checkpoint generator 46 , the toolpath generator 48 and the synchronization routine 50 will now be described with reference to FIGS. 5A, 5B and 6.

Operation begins at decision block 80 ( FIG. 5A), where the control point generator 46 divides the data values 60 a- 60 l into groups of four and determines whether each of the four ( 4 ) image data values, such as the values 60 a- 60 d in Figure 3 illustrates a halftone ("CT") image. In this context it should be reported executed that the image data values 60 a- 60 d an image intensity value and an indicator include that relating to the data source between "CT" and "LW" is different. If the decision at decision block 80 is negative, the image data value received from control point generator 46 by controller 38 represents a line work ("LW") image.

The control point generator 46 selects (block 81 ) corresponding setup values (not shown) which are used in the processing of the LW image data value. The setup values used in this processing include the WS gain, the GS gain, and the shift values as taught in OEE Patents 5,424,848 and 5,621,533, which are hereby incorporated by reference into this specification and form part of it. If the decision at decision block 80 is yes, the image data value represents a CT image and the routine proceeds to block 82 where it selects the CT setup values used by checkpoint generator 46 .

The routine proceeds to block 84 further, where the control point generator 46 determines a plurality of pulse frequency dividers which are used to the image data values 60 a- 60 d to scale (Fig. 3). The control point generator 46 first determines or calculates a pulse frequency divider for full cell depth (block 84 ) using the CT setup values, and a pulse frequency divider for channel depth (block 86 ) is also calculated using the CT setup values.

At blocks 88 and 90 ( FIG. 5A), a pulse frequency divider for the full cell depth for LW and a pulse frequency divider for the channel depth for LW are calculated.

After blocks 86 and 90 , the routine continues to block 92 where the control point generator 46 calculates a total density as a percentage of the sum of four (4) image data values. At decision block 94 , it is determined whether the total density is less than one percent (1%), which would indicate an area not engraved. If this is the case, the routine proceeds to block 96 , where the control point generator 46 assigns and stores control points which result in the engraving tip 30 being positioned over the surface 25 a of the cylinder 24 during the actual engraving. The routine is then completed.

If the decision at decision block 94 is negative, the routine continues to decision block 98 ( FIG. 5B) where it is determined whether a multi-frequency cell or an engraved area is needed. In the described embodiment, the answer to the multi-frequency decision (block 98 ) is yes, if both conditions are met, where the first data value is greater than the sum of the second and third data values (for example 60 a <( 60 b + 60 c) ), and the fourth data value is greater than the sum of the second data value and the third data value (for example 60 d ( 60 b + 60 c)).

FIG. 4 shows a further stream 66 of image data values, which comprises a plurality of density values 66 a- 66 l. Note that in the figure shown in Fig. 4, the density values 66 e- 66 h show density values from black (100%) to white (0%) to white (0%) to black (100%), thereby indicating multi-frequency engraved areas because 66 e <( 66 f + 66 g) and 66 h <( 66 f + 66 g).

The engraved areas represented by these density values are represented by the engraved areas 65 a and 65 b, which are defined by the tool path 65 , which was generated with the aid of the density values 66 a- 66 l. The creation and execution for creating the toolpath 65 ( FIG. 4), which represents several engraved areas, is described below.

If the answer to decision block 98 ( FIG. 5B) is negative, a more frequency-engraved area is not required and the routine proceeds to block 100 where an entry control point or position and depth is determined. In this regard, an entry point, such as point 62a in Fig. 3, is determined and an entry depth (indicated by Ed in Fig. 3) is determined by applying the appropriate CT or LW channel pulse frequency divider to the first image data determined, which in this example is 60 a. It should be noted that the depth Ed is the depth with which the engraving tip 30 penetrates into the surface 24 a. Similarly, at block 102, a midpoint position 62b and a midpoint depth (identified as Cd in FIG. 3) are determined. The mean depth Cd is determined using the full depth pulse rate divider on the previously calculated total percent density (block 102 in FIG. 5B). The center position is determined by calculating the center of the image density of the data values 60 a- 60 d and searching for the control point 62 b, so that an equal amount of density is present on the left and right of 62 b. The center of the engraved cell is thus shifted towards the denser image data values in order to improve the quality of the image reproduction. This feature is in relation to the engraved area 75 in Fig. 4A and the therewith associated control point 71 illustrated a- c 71. The routine proceeds to block 104, where a point of exit position (marked as item 62 c in Fig. 3) and an associated outlet Exd depth is determined at block 104. The routine is then complete.

If a multi-frequency engraved area is required, the decision at decision block 98 is affirmative. The routine runs, as shown, to block 106. where the control point generator 46 continues so, control points such as the points 70 a, 70 b and 70 c, for the first subset of image data values 66 e and generating f 66, and Control points 70 d, 70 e and 70 f for the second image data subgroup, which is represented by the density values 66 g and 66 h.

As shown in FIG. 4, the routine divides the image data value stream 66 into subgroups to four data values, which represent several engraved areas. In the illustration described and shown in FIG. 4, the associated tool path 65 is ultimately generated by the Drive engraving tip 30 accordingly to engrave dual or double frequency engraved areas, such as areas 65 a and 65 b, which are shown in Fig. 4. The process of execution for processing multi-frequency data values will now be described.

At block 106 in FIG. 5B, the control point generator 46 calculates 46 an overall density for the first pair of data values, such as the data values 66 e and 66 f in Fig. 4. The routine proceeds to block 108 where the Kontrollpunktgenera tor a Center of image density for this first pair of data values. At block 110, the control point generator 46 determines then troll point position a first Eintrittskon, such as the control point 70 a, which is in Fig. 4 Darge, and the corresponding entry depth. The first entry point depth is determined using the first data value 66 e and by applying the channel depth pulse frequency divider thereon. At block 112, the determined Kontrollpunktgenera gate 46, a first center position (point 70 b in Fig. 4) and the depth. The first center point 70 b is placed in the center of the image density and the depth associated with it is adjusted by applying the full depth pulse frequency divider to the percent total density for the first pair of data values 66 e and 66 f. At block 114 , a first exit position (point 70 c) and the associated depth are determined.

The engraving tip 30 emerges from the surface 24 a at the exit point 70 c. This point 70 c is a distance D ₁ ( FIG. 4) to a starting point SP. This distance D ₁ changes relative to the total distance D ₂ in the same ratio as the total percent density calculated at block 106 in FIG. 5B.

The control point generator 46 then continues to determine the control points 70 d- 70 f associated with the second image data subset (values 66g and 66h in the illustration shown in FIG. 4). Accordingly, the control point generator 46 determines at block 116 ( FIG. 5B) an overall density for the second pair of data values 66 g and 66 h. At block 118 , control point generator 46 searches for a center of image density for the second image data subset. At block 120 , a second entry position and a depth control point (point 70 d in FIG. 4) are then determined. The engraving tip 30 enters the surface 24 a at the entry point 70 d. This point 70 d is a distance D ₃ ( FIG. 4) to an end point EP. This distance D ₃ changes relative to the total distance D ₂ in the same ratio as the total percent density calculated at block 116 in FIG. 5B.

The routine continues to block 122 ( FIG. 5B) where a second center position (point 70e ) and a depth control point are determined. The second center point 70 e ( FIG. 4) is placed at a center of the image density of the second pair of data values 66 g and 66 h. The second midpoint depth is determined using the full depth pulse rate divider (determined at block 84 for CT data or 88 for LW data in FIG. 5A) on the percent total density (block 116 in FIG. 5B) for the second pair of data values 66 g and 66 h. At block 124 , a second exit position (point 70 f) and a depth control are determined. The depth of the second exit point 70 f is determined using the last data value 66 h and using the channel depth pulse frequency divider (block 86 or 90 in FIG. 5A).

After all of the control points 70 a- 70 f from the control generator 46 are generated, they are transmitted to the curve fitter / Werkzeugweggenerator 48, the a generated control points 70 processes 70 f, in the memory, such as 32406 00070 552 001000280000000200012000285913229500040 0002019823792 00004 32287 as a checkpoint buffer (not shown) can be saved. The control point generator 46 interpolates or "fit" a corresponding curve of the control points 70 a- 70 f in to the tool path (such as the tool path 65 in Fig. 4) to generate. This tool path 65 is stored in memory, such as an output buffer (not shown), and subsequently used to generate an engraving drive signal to excite the engraving head 28 .

The digital signal processor 42 also includes the previously mentioned synchronization device or synchronization routine 50 for receiving machine synchronization signals from the engraving controller 38 and for synchronizing the generated tool path, such as the tool path 64 or 65 , with the engraving machine 10 . The synchronization routine will now be described with reference to FIG. 6. The routine begins at block 126 by reading a section, such as section 64d ( FIG. 3) of toolpath 64 .

The routine transfers the generated toolpath to the fine tuning processor 52 ( FIG. 2) for use in the manner to be described below (block 128 in FIG. 6).

The routine also collects the incoming image data stream 60 and, for example, causes the toolpath 64 to be generated in response. It should also be noted that the routine of the controller 38 image data 60 (for. Example, the values 60 a- 60 d in Fig. 3) at a rate of 4 data values for each single frequency engraved area such as the area 67 ( Fig. 3) receives. Substantially simultaneously thus transmits the routine, the data of the tool path 64 for fine adjustment processor 52 having a Ge speed of 32 data values or segments (such as management of the Seg 64 d in Fig. 3) per single frequency engraved area (such as the region 67 in FIG . 3).

The routine then proceeds to block 130 ( FIG. 6) where the image data stream 60 ( FIG. 3) is received by the controller 38 with 4 data values (e.g. 60 a- 60 d) per single frequency engraved area.

Thereafter, the image data, such as the data 60 a- 60 d, stored by the tool path control 44 in an appropriate memory.

At decision block 134 it is determined whether the four (4) image data values, such as values 60 a- 60 were received d in Fig. 3 of the tool path control 44th If not, the routine ends. When the image data values were received, the routine continues to block 136 (Fig. 6), where the data values 60 a- 60 d in the control points 62 a- 62 c under appli cation of the aforesaid control point generator 46 to the above-zugnahme under loading on Figures 5A and 5B are processed in the manner described.

At block 138 , the control points are further processed by the toolpath generator 48 into the toolpath, such as the toolpath 64 in FIG. 3, as previously described herein. The synchronization routine or device is then completed and the tool path is synchronized with the operation of the engraving machine 10 .

Advantageously, this invention synthesizes the digital image data stream 60 and the conventional scanning function into a reference tool path or waveform that represents the desired tool path that the graphical tip 30 is to follow. It should be noted that the conventionally used scanning is synthesized directly from the digital image data, thereby allowing much greater flexibility and improvement in engraving quality.

In the described embodiment, the image data are converted into the control points mentioned above, at which the engraving tip 30 enters for each area to be engraved (such as area 67 in FIG. 3) (point 62 a in FIG. 3), the maximum Reach depth (point 62 b in Fig. 3) and exit (point 62 c in Fig. 3). As previously mentioned herein, the control points are then used by the curve adjuster / toolpath generator 48 to generate, interpolate, or "adjust" the toolpath, such as the toolpath 64 , to determine the engraving path that the engraving tip 30 will follow . As a result, the toolpath 64 is generated and used as the toolpath for the engraving tip 30 , which is derived directly from the digital image data.

Another feature of the invention is that the apparatus and method of the present invention enables the digital distortion of the tool path generated, for example around one or more centers of engraved areas or partially engraved areas, particularly at the edges of an image (not shown), to postpone. Thus represent, as shown in Fig. 4A can be seen, the image values 69 a- 69 d densities of 100% (solid black), 100% (full black), 0% and 0%. Most prior art engraving systems average these densities to produce a 50% density cell (not shown) that is generally in the center of region 74 .

In contrast, the present invention and the control point values generator 46, the image data, and generate corresponding control points 71 a-71 c, as shown. These control points 71 a- 71 c are then used by the tool path generator 48 to generate the tool path curve 73 .

It is noted that the tool path defining a shifted engraved area 75, the more specific b speaks ent the image data originally input 69 a and 69th

This feature enables a great improvement in the quality of the engraved images. In this connection, reference is made to FIG. 17, where a Kanji character is shown as pattern X, which was engraved using conventional engraving technology. In contrast, pattern Y ( Fig. 16) was engraved using the apparatus and method of the present invention. Note that the horizontal lines X1 and Y1 (as shown in Fig. 16) show an improved arrangement of the engraved areas, which was achieved by shifting an engraved area or a portion thereof from positions such as X2, which of conventional engraving techniques would be required.

The invention further provides a fine-tuning device, a fine-tuning processor, a fine-tuner or a fine-tuning system 52 ( Fig. 2) and a method for calibrating and fine-tuning the engraving head 28 so that it will follow the tool path generated in a desired or precise manner. The fine adjuster 52 is coupled to the engraving head 28 via the amplifier 53 , the amplifier amplifying the engraving signal received by the fine adjuster 52 to excite the movement of the engraving tip 30 on the engraving head 28 .

Fig. 9 shows a raw engraving head response characteristic 53 , which shows a large number of tips, such as the tips 53 a and 53 b, which are associated with a first resonance and a second resonance of the engraving head 28, respectively. As is conventionally known, the first and second resonances in a typical engraving head typically occur at about 1800 kHz and at about 5500 kHz. As is also conventionally known and as shown in Fig. 10, a typical engraving system includes a plurality of notch filters located on the engraving head 28 which eliminate the aforementioned first and second resonances to provide a response characteristic 57 which is generally uniform but is substantially continuously decreasing, as shown in FIG. 10.

Advantageously, the apparatus and method of the present invention includes a boost filter device or filter 56 for processing the engraving signal to provide a substantially constant gain or linear response characteristic of the type shown by response characteristic 58 in FIG. 11. Note that the response characteristic 58 is substantially linear over a wider frequency range to allow a substantially constant gain for frequencies approaching or below the 10,000 kHz range. In general, the apparatus and method of the present invention accomplishes the above by amplifying the engraving signal at frequencies greater than an emphasis frequency, which in the described embodiment is at least 1 kHz.

In order to achieve the type of response characteristic shown in FIG. 11, the fine adjustment device 52 includes at least one or a plurality of filters 54 and 56 , the tool path (such as tool path 64 in FIG. 3) generated by the digital signal processor 42 , processed or filtered. After the notch filter 54 has processed the toolpath 64 to eliminate the above-mentioned first and second resonance, the boost filter 56 is applied to filter the signal to achieve the response characteristic 58 shown in FIG. 11.

In the described embodiment, the notch filtering can be performed by a individual infinite impulse response filter algorithm can be achieved in one Digital signal processor, such as. B. an ADSP21062 available from Analog Devi ces Inc. of One Technology Way, PO Box 9106, Norwood, MA 02062, im is implemented. A second infinite pulse of the response filter can be created to implement the emphasis filter of the present invention.  

One algorithm that can be used to implement the notch and boost filtering provided by filters 54 and 56 is the infinite impulse response (IIR) Bi quad filter as used in ADSP -21000 Application Handbook, Volume 1, Section 4.2-IIR Filter by Analog Devices, available from Analog Devices Inc. of Norwood, MA, and published in May 1994.

It should be noted that the boost filter 56 enables a substantially linear or flattened frequency response (response 58 in FIG. 11) after the notch filter 54 has modified the response curve with a desired response characteristic so that the response of the engraving head 28 will allows the same amplitude over a larger frequency range. This is particularly advantageous when double-frequency engraved areas of the type illustrated and described above with reference to FIG. 4 are engraved or implemented, since the filtered engraving head 28 has at least 50% of the maximum amplitude, for example at a frequency of 10 kHz , as presented, must achieve.

In the described embodiment, the fine adjustment device 52 further includes a fine adjustment computer, an interface device or a user interface 150 ( FIG. 2) for configuring both the notch filter 54 and the emphasis filter 56 . This interface 150 may include application software running on an IBM PC or an IBM-compatible PC, which generates an interactive interface screen 150 a ( FIG. 12). In this regard, the user interface screen 150 a may include a window 150 b for entering and / or setting parameters for the notch filter 54 and the emphasis filter 56 . In the described embodiment, the filter parameters include a frequency value 152 and a notch depth value 154 for each of the notch filters 54 . A similar user interface screen (not shown) is also created for similar filter parameter values for the enhancement filter 56 . In the described embodiment, the user interface 150 ( FIG. 2) converts the parameter information into filter coefficients using the following coefficient formulas:

C ₁ = 2C0S (0.000005 * 2 * II * FREQ * 1-DAMP ² ) *

_e (-0.000005 * 2 * II * FREQ * DAMP)

C ₂ = _(e (-0.000005 * 2 * II * FREQ * Damp) ₎ ²

wherein: "C ₁ " and "C ₂ " are the IIR filter coefficients used by filters 54 and 56 , respectively;
"FREQ" is the frequency value entered by the user via the user interface 150 ( FIG. 2) ( FIG. 2); and
"DAMP" is the attenuation value for filters 54 and 56 that is entered by the user through user interface 150 .

"II" is the universal constant 3.14159. . .

The calculated coefficients C ₁ and C ₂ are then used to electronically adjust the current coefficients of the notch filters 150 and 152 .

Advantageously, this invention provides a device that enables a user to program or adjust the filter coefficient values interactively, allowing the user to program or change the frequency characteristics of the engraving head 28 electronically without having to do with the engraving head 28 change related hardware, such as filters.

The engraving system 10 further includes a digital automatic Rückmeldevor direction or a feedback control 156 ( Fig. 2), which contributes to the stabilization of the engraving head 28 by implementing electronic damping of the natural resonances of the engraving head 28 . In the described embodiment, the feedback control 156 is coupled to a sensor circuit 158 ( FIG. 14) which determines a position of the engraving tip 30 and a speed of the engraving tip 30 and sends the data to the feedback control 156 ( FIG. 2).

In this regard, Figure 13 shows a cross section of a typical rotor 170 immovably attached to a shaft 172 and projecting outwardly between a pair of electromagnets 174 mounted within a machine bed of the engraving head 28 , such as in the US -Patents Nos. 5,029,011, 4,450,486, 4,438,460 and 4,357,633, all of which have been assigned to the same assignee as the present invention and which are hereby incorporated by reference into this specification and are incorporated therein. The rotor 170 works with the electromagnets 174 to define air gaps 176 . In a well known manner, when the electromagnets 174 are energized by an alternating current, the rotor 170 and the shaft vibrate to a maximum arc of about 0.25 degrees and at a frequency of, for example, 3-5 kHz. In a known manner, the engraving tip 30 is attached to the shaft 172 via a holding arm (not shown) and subsequently vibrates in response to the vibration of the shaft 172 .

The electromagnets 174 are excited in a conventional manner with the aid of the windings 178 .

Sensor circuit 158 includes a second group of windings 180 located around electromagnet 174 . In the described embodiment, the windings 180 comprise a sensor coil for measuring the magnetic flux that is present in the electromagnet of the rotor 170 , which converts the feedback control or the feedback device 156 into a current position of the engraving tip 30 . The magnetic flux present in the electromagnet is the sum of two sources, namely the drive windings 178 and the flux induced due to the movement of the rotor. The windings 180 sense the magnetic flux present in the motor, and an electronic circuit ( 158 in FIG. 14) subtracts the flux of the windings 178 to obtain the flux component of the speed of the rotor 170 .

The device or circuit 158 includes a current sensing resistor 182 , as shown, between the ground and a low (-) side of the engraving head 28 . The circuit 158 also includes a Empfängerver more 184 to the high (+) winding 178 A of the top drive and at the low (Fig. 13) (-) winding 178 B of the top drive is coupled to produce an amplified signal is integrated by the integration amplifier 186 . The resulting integrated signal is transmitted as an input to a summing amplifier 188 , as shown in FIG. 14.

Circuit 158 also includes a receiving amplifier 190 which, as shown, connects to a high (+) side 180 A of the head cooling in Fig. 13 and a low (-) side ( 180 B in Fig. 13) of the head cooling and across the Stromsen sensor resistor 182 ( Fig. 14) is coupled. The receiving amplifier 190 receives the measured signals and generates an amplified output signal which is received as a second input from the summing amplifier 188 and as the only input from a differentiator amplifier 192 , as shown.

The outputs of the differentiator amplifier 192 and the receiving amplifier 184 are received by the summing amplifier 194 . The summing amplifiers 188 and 194 each sum their respective received inputs and generate or output a position signal and a speed signal, respectively. It has been shown that the position signal and the speed signal coincide with the position and the speed of the rotor 170 and the engraving tip 30 .

The picked up signals are fed back to a user interface decoder 154 ( Fig. 2). The interface decoder 154 provides the user with response data to the engraving head 28 via the user interface 150 in the manner previously described herein.

The system and method of the invention include an apparatus for providing interactive and automated fine adjustment of the engraving head 28 , which will now be described with reference to FIGS. 7 and 8. The routine begins at block 200 where the fine tuning processor 52 receives the most recently transmitted value for the toolpath 64 from the toolpath controller 42 . The routine proceeds to block 202 where the toolpath value from notch filter 54 is processed using the fine tuning filter coefficients generated by user interface 150 using predetermined coefficients or filter coefficients generated in response to parameters that are generated by a user through the User interface 150 have been entered.

At block 204 , the routine processes the value of the toolpath with the enhancement filter 56 using the enhancement filter coefficients entered via the user interface 150 using predetermined coefficients or filter coefficients generated in response to parameters created by a user via the user interface 150 have been entered.

At decision block 206 it is determined whether a user A has entered a fine adjustment parameter update instruction by input of a new or another parameter using the user interface 150, in which case the new filter coefficients for the filter 54, which are generated by the user interface 150, from the fine adjustment processor 52 are stored in a suitable buffer (not shown) (block 209 in FIG. 7).

If the decision at decision block 206 is negative, the routine proceeds to block 208 where it is determined whether a user has entered new boost filter parameters, thereby indicating an upgrade command for boost filter 56 . If so, the routine continues to block 210 where new boost filter coefficients generated by user interface 150 are stored in a suitable buffer (not shown) by fine tuning processor 140 .

If the decision at decision block 208 is negative, the routine proceeds to decision block 212 , where it is determined whether a head response test command at interface decoder 154 has been received by user interface 150 . If so, the routine continues to test the engraving head 28 with a test pattern that is sent to the engraving head 28 . During this test, the feedback controller / device 156 generates feedback or measured information regarding the current position and speed of the engraving tip 30 in the manner previously described herein. The recorded data regarding position and speed are routed back to the interface decoder 154 and ultimately to the user interface 150 in a manner to be described later with reference to FIG. 8.

If decision block 212 is negative or blocks 209 , 210 and 214 have completed, the routine is complete.

Fig. 8 shows the interactive / automated fine adjustment user interface of lenvorrichtung or routine which begins at block 220 where information is input from a user via the user interface 150. In the described embodiment, such information may include, for example, an automatic tuning request, filter parameter information such as filter notch depth, filter frequency change requests, and / or a head response request command, as mentioned above, to check the responsiveness of the engraving head 28 .

In this regard, the user interface screen 150 may include a electronic keys (not shown) which enable an operator to select these different commands or enter.

The routine continues to decision block 222 where it is determined whether a user has entered a request to change a frequency or notch depth of filter 54 . If so, the routine continues to block 224 where the user interface computer 150 recalculates the filter coefficients for the filter 54 and sends it to the fine tuning processor 52 and then aborts. As mentioned hereinbefore, FIG. 12 shows a suitable user interface 150a that enables a user to enter such information.

If the decision at decision block 222 is negative, the routine proceeds to block 226 , where it is determined whether the frequency change of boost filter 56 has been requested by the user. If so, the routine proceeds to block 228 where user interface 150 recalculates the filter coefficients in response to the new frequency entered by the user and sends them to fine tuning processor 52 and then aborts. After the Neube the filter coefficient calculations for the filters 54 and 56 150 sends the interface the new notch filter coefficients and emphasis filter coefficients to the notch filter 54 and the peaking filter 56, to adjust the filters 54 and 56 in response to electronically, as previously described herein.

If the decision at decision block 226 is negative, the routine proceeds to decision block 230 , where it is determined whether the user has entered an automatic tuning request. If so, the interface decoder 154 sends the command to perform a head response test to the feedback controller / device 156 (block 232 ). At this point, the fine adjustment processor 52 stops processing the current work zeugwegdaten received via the line 52 a of the tool path controller 44, and begins to process the test pattern data stored in the memory of the fine adjustment processor 52nd

After the test pattern is engraved, the feedback controller / device 156 receives the captured and current position of the engraving tip 30 , which was captured by the sensors 158 ( FIG. 14) as previously described herein. This information is transmitted back to decoder 154 and to user interface computer 150 for display and evaluation (block 234 ).

If the user interface computer 150 determines that there is an unacceptable difference between the current response of the engraving tip 30 and the desired response of the engraving tip 30 , the user interface computer 150 electronically recalculates and resets the filter coefficients C ₁ and C _{2 in} response accordingly (block 236 ).

Advantageously, it should be noted that this invention provides an apparatus and method for automatically fine-tuning an engraving head 28 in response to an automatic fine-tuning request requested by a user.

At block 238 , new and / or set filter coefficients are sent to filters 54 and 56 , thereby automatically adjusting the response characteristic 58 ( FIG. 11). After block 238, or if the decision at decision block 230 is negative, the routine ends.

Fig. 15 shows a schematic representation of an entire operation process, which begins when the system, wherein the tool path control start 44 (block 240), the fine adjustment processor (block 242) and the interakti ve / automated fine adjustment computer 150 (block 244). At decision block 246 , it is determined whether a user has entered a tuning modification request, and if he has not, the routine is repeated as shown (decision block 246 ). If the decision at decision block 246 is yes, the routine continues to block 248 where the user interface routine (described with reference to FIG. 8) is executed. Thereafter, the routine returns to decision block 246 , as shown.

The fine adjustment processor 52 includes an internal clock or timer (not shown) that is set to periodically run 200,000 times per second. If it is determined at decision block 250 that the timer has expired, the routine proceeds to block 252 where the fine tuning processor routine described with reference to FIG. 7 is executed. Thereafter, or if the decision made at decision block 250 is negative, the routine returns to decision block 250 as shown.

At decision block 254 , it is determined whether a machine synchronization signal (not shown) has been received by the digital signal processor 42 from the engraving controller 38 . If so, the toolpath control synchronization routine described above with reference to FIG. 6 is executed. Thereafter, or if the decision at decision block 254 is negative, the routine returns to block 254 as shown.

Although the method described here and the form of the device for Execution of this method preferred embodiments of this invention represent, it must be pointed out that the invention is not accurate this method and the design of the device is limited and that Changes can be made to both without sacrificing protection deviate scope of the invention, the festge in the following claims sets is.

Claims (51)

1. A method for engraving a workpiece with a pattern of engraved areas on a workpiece, comprising the following steps:

• - The generation of image data that correspond to an image to be engraved;
• - deriving a tool path directly from the image data;
• - Using the toolpath to determine an engraving signal; and
• - Excitation of an engraving head to engrave the workpiece using the engraving signal.

2. The method of claim 1, the method further comprising the steps of:

• the generation of a plurality of control points which correspond to the image data.

3. The method of claim 1, the method further comprising the steps of:

• generating control points corresponding to the image data;
• - fitting a curve to the control points to generate the tool away.

4. The method of claim 1, the method further comprising the steps of:

• - performing the derivation step using an interpolation routine of a cubic spline.

5. The method of claim 1, the method further comprising the steps of:

• - processing the image data to produce a predetermined number of density values;
• using the predetermined number of density values to determine a total image density in percent.

6. The method of claim 5, the method further comprising the steps of:

• using the predetermined number of density values to determine a density center.

7. The method of claim 1, the method further comprising the steps of:

• - Establishing an entry control point at which a tool on the engraving head enters the workpiece;
• - Establishing an exit control point at which a tool exits the workpiece on the engraving head;
• - Establishing at least one other control point between the entry control point and the exit control point.

8. A method of control according to claim 7, the method further comprising the steps of:

• - establishing a middle control point between the entry control point and the exit control point;
• - Using the entry control point, the exit control point and the middle control point to determine the tool path.

9. The control method of claim 7, the method further comprising the steps of:

• - establishing a middle control point between the entry control point and the exit control point;
• - fitting a curve to the entry control point, the exit control point and the middle control point to define the tool path.

10. The method of control of claim 9, the method further comprising the step of:

• - the establishment of a central control point, which corresponds to a center of an image density.

11. A method of control according to claim 7, the method further comprising the steps of:

• determining an overall image density in percent for a section of the image data, the section corresponding to an engraved area to be engraved;
• - Using the total image density in percent to set up the entry control point and the exit control point.

12. The method of control of claim 1, the method further comprising the step of:

• - Setting up the entry control point and the exit control point on a surface of the workpiece.

13. The control method of claim 7, the method further comprising the steps of:

• - Setting up the entry control point and the exit control point under a surface of the workpiece when the total density in percent exceeds a predetermined percentage.

14. The method of claim 13, wherein the predetermined percentage is at least 90%.   15. The method of claim 1, wherein the image data comprises first image data and second image data, the method further comprising the following steps:

• determining whether a summed image density for the first image data and the second image data comprises a majority of the density for all image data;
• dividing the first image data and the second image data into a first image data subgroup and a second image data subgroup;
• - The generation of control points for the first image data subgroup and the second image data subgroup.

16. The method of claim 1, wherein the image data comprises a plurality of image data groups, the method further comprising the following steps:

• - determining whether a summed density for the plurality of image data groups is greater than a density for all image data;
• dividing the plurality of image data groups into a plurality of image data subgroups;
• the creation of control points for each of the plurality of image data sub-groups.

17. The method of claim 1, the method further comprising the steps of:

• - determining a frequency of image data values to represent at least a portion of the image to be engraved on the workpiece to create a predetermined number of image density values;
• generating a plurality of control points using the predetermined number of image density values.

18. A tool path control device for controlling a path for a tool on the engraving head in an engraving machine, comprising:

• an image data processor for generating control points in response to the image data, the image data processor further comprising a tool path generator for processing the control points to define a tool path; and
• - A signal generator, which is coupled to the image data processor and the engraving head to receive the tool path and excite the engraving head to move the tool in response to the tool path for engraving the workpiece.

19. The tool control device of claim 18, wherein the image data processor processes the image data to provide a predetermined number of density values, the image data processor further comprising:

• an image density determination device for receiving the predetermined number of density values and for determining an overall image density in percent.

20. The tool path control device of claim 18, wherein the tool path control device further comprises:

• a density center determining device for receiving the predetermined number of density values and for using the predetermined number of density values for determining a density center.

21. The tool path control device for control according to claim 18, wherein the tool path generator further comprises:

• - A control point generator for identifying an entry control point at which the tool enters the workpiece, an exit control point at which the tool exits the workpiece, and at least one other control point between the entry control point and the exit control point.

22. The tool path control device for control according to claim 21, wherein the control point generator further comprises:

• a midpoint identification device for identifying a central control point between the entry control point and the exit control point;
• wherein the toolpath controller is able to generate the toolpath in response to the entry control point, the exit control point, and the center control point to define the toolpath.

23. The tool path control device for control according to claim 21, wherein the image data processor further comprises:

• - A curve adjuster for receiving the entry control point, the exit control point and the at least one other control point and for generating a curve which corresponds to these points.

24. Tool path control device for control according to claim 21, wherein the image data processor receives the image data and an overall image density determined as a percentage and the total image density used as a percentage Establish entry control point and exit control point. 25. tool path control device for control according to claim 21, the toolpath generator the entry control point and the exit control Trollpunkt on a surface of the workpiece when a previous agreed condition. 26. Tool path control device for control according to claim 25, the predetermined condition comprising a density less than one predetermined density. 27. Tool path control device for control according to claim 26, the predetermined density being less than 90%. 28. The tool path control device according to claim 18, wherein the image data comprises first image data and second image data, the tool path control further comprising:

• a double frequency determiner for determining whether a summed image density for the first image data and the second image data comprises a majority of the density for all image data;
• - The double frequency determiner divides the first image data and the second image data into a first image data sub-group and a second image data sub-group if the image density exceeds a majority, and generates control points for the first image data sub-group and the second image data sub-group.

29. The toolpath control device of claim 23, wherein the curve adjuster further comprises:

• - an interpolation routine of a cubic spline to generate the tool curve.

30. Engraving machine for engraving a workpiece, comprising:

• - an engraving bed;
• - An engraving head, which is located on the engraving bed in order to engrave at least one engraved area on the workpiece, the engraving head comprising a tool;
• - A processor which is coupled to the engraving head to receive image data and also to generate an engraving signal for engraving at least one engraved area; and
• a digital toolpath planner that is associated with the processor to plan a toolpath in response to the image data, the processor using the toolpath to generate the engraving signal.

31. The engraving machine of claim 30, wherein the processor further comprises:

• a toolpath data signal processor for receiving digital image data associated with an image to be engraved and for generating the toolpath in response thereto.

32. The engraving machine of claim 30, wherein the processor further comprises:

• a toolpath data signal processor for receiving the image data associated with the image to be engraved and for generating a plurality of control points in response thereto.

33. The engraving machine of claim 30, wherein the processor further comprises:

• - A curve adjuster for receiving the plurality of checkpoints and for adapting a curve thereon, the curve defining the tool path.

34. The engraving machine of claim 32, wherein the processor further comprises:

• - A curve adjuster for receiving the plurality of checkpoints and for adapting a curve thereon, the curve defining the tool path.

35. Engraving machine according to claim 33, wherein the plurality of control points generally corresponds to an entry point at which the tool the engraving of an engraved area of the at least one engraving area begins, an exit point where the tool hits one of the at least one leaves an engraving area, and a third control point between the entry point and the exit point. 36. The engraving machine according to claim 35, wherein the third point is one Includes center, which corresponds to a density center of the image data. 37. The engraving machine of claim 30, wherein the processor processes the image data to create a predetermined number of density values, the processor further comprising:

• an image density determiner to receive the predetermined number of values and to determine a total image density in percent.

38. The engraving machine of claim 37, wherein the processor further comprises:

• a density center determining device for receiving the predetermined number of density values and for using the predetermined number of density values to determine a density center.

39. Engraving machine according to claim 30, wherein the processor the image data receives and determines an overall image density in percent and the total Image density in percent used to control a variety of control points Determine the tool path to be determined. 40. Engraving machine according to claim 33, wherein the tool path data signal processor the entry control point and the exit control point at one Surface of the workpiece when a predetermined condition occurs sets up. 41. The engraving machine according to claim 40, wherein the predetermined one Condition includes a density that is less than a predetermined density. 42. The engraving machine according to claim 41, wherein the predetermined one Density is less than 90%. 43. The engraving machine according to claim 9, wherein the image data is first image data and second image data, the processor further comprising: a dual frequency determiner for determining whether a summed image density for the first image data and the second image data comprises a majority of the density for all image data;

• - The double frequency determiner divides the first image data and the second image data into a first image data sub-group and a second image data sub-group if the image density exceeds a majority, and generates control points for the first image data sub-group and the second image data sub-group.

44. The engraving machine of claim 34, wherein the curve adjuster further comprises:

• - an interpolation routine of a cubic spline to generate the tool curve.

45. The engraving machine of claim 31, wherein the digital tool path data signal processor further comprises:

• a pulse frequency divider generator for determining whether the image data is halftone data or line work data, in order to generate either a pulse frequency divider for halftone data or a pulse frequency divider for line work data if it is determined that the image data is halftone data or line work data, and to apply either the halftone data pulse frequency divider or the linework data pulse frequency divider to the control points prior to the processing step.

46. A speed measuring system for measuring a speed of a cutting tool for engraving a cylinder, comprising:

• - a runner for holding the cutting tool;
• - At least one electromagnetic drive, comprising at least one drive coil around it, in order to set the rotor in vibration when the at least one drive coil is excited; and
• - A sensor, which is arranged in operative relationship with the at least one electromagnetic drive to determine a cutting tool position in response thereto.

47. The speed measurement system of claim 46, wherein the sensor comprises:

• - A sensor coil, which is arranged around the at least one electromagnetic drive;
• a sensor circuit coupled to the sensor coil to measure a speed of the rotor and convert the speed to the cutting tool position.

48. Speed measuring system according to claim 46, wherein the sensor spool a rate of change of flow through the at least one Drive coil measures.   49. Speed measuring system according to claim 47, wherein the sensor do not wind more than five turns around the electromagnetic drive includes. 50. Speed measuring system according to claim 46, wherein the speed digkeitsmeßsystem includes a position sensor.